Severe thunderstorms knocked out power to 1.2 million homes in the D.C. area. Wildfires ravaged more than 2 million acres in the Rockies. Two-thirds of the country is in drought conditions, and flooding is expected to get worse as the time between rainstorms lengthen and, in turn, grow more intense.

Intensifying weather patterns threaten businesses as global warming raises the temperatures of the oceans. Disaster recovery plans that include only backing up data regionally may need to be rethought, experts say.

The cloud, which was supposed to guarantee high availability, has been significantly affected by power outages caused by storms. Companies dependent on cloud service provider Amazon Web Services (AWS) found their websites down a week ago when rare severe thunderstorms, known as derechos, struck the Virginia and Washington D.C. area, leaving 1.2 million homes without power for days.

"We thought that by simply deploying [our website] across multiple active zones on Amazon we were going to have the backup we needed," said Brandon Wade, CEO of WhatsYourPrice.com, an online dating site with 400,000 active members. Wade said his site went down twice, for two hours each time after Amazon lost power. More than 1,000 customers contacted WhatsYourPrice.com to complain, he said.

WhatsYourPrice.com had initially signed on with Amazon's AWS 18 months ago because using a service provider reduced costs for the start-up. But, after two outages at Amazon in less than a month, WhatsYourPrice.com canceled the cloud service, and is now deploying its servers in two co-location facilities, as well as using a local Las Vegas cloud provider for data backup.

"If your business can take a few hours of outage when a disaster strikes, then [Amazon AWS] is the solution to have," Wade said. "Otherwise, you need to architect in a smarter way."

Derechos, which are caused by severe heat waves and can develop hurricane-force winds, can span hundreds of miles. The storm on June 29 spanned some 700 miles and had average wind speeds of 60 mph.

"In the thunderstorm on Friday night, several of our data centers had their utility power impacted, but in only one of them did the redundant power not operate correctly (which ended up impacting a single digit percentage of our Amazon EC2 instances in the US-East Region). We began restoring service to most of the impacted customers Friday night, and the remainder were restored on Saturday," the spokesperson wrote in an email response to Computerworld.

A firefighter works a burnout operation on the north flank of the Fontenelle Fire outside Big Piney, Wyoming. More intensive natural disasters such as wildfires and derechos are requiring companies to pay more attention to disaster recovery planning. (Photo: Jim Urquhart / Reuters)